A flatblend, that contains mid-fractions of both hardened and fractionated soy bean oil and cottonseed oil are known. A commercial product, Kaomel from Unilever, contains the mid-fractions mentioned above. This product already shows a reasonable to good gloss-retention of chocolate coatings, when used in it. We have now found a new fatblend, that provides an even better gloss-retention when used in chocolate coatings.
Thus our invention concerns in the first place fatblends, comprising a mid fraction of hardened fractionated soy bean oil and a mid fraction of hardened, fractionated cottonseed oil, wherein the weight ratio of the two mid-fractions ##EQU2## is less than 1,0, preferably this ratio is 10:90-40:60, most preferred is a ratio of 25:75-35:65.
By using these blends in chocolate coatings can be obtained with excellent gloss-retention, whereas the N-values of these blends are according to the standards, required for such blends. Especially the N.sub.30 and N.sub.35 values, which are very important, are in accordance with these standards.
Because of the excellent gloss-retention of our composition it is no longer necessary to add an emulsifier to the composition in order to improve the gloss-retention.
Sometimes it is helpful, e.g. when the hardness of the blend needs to be corrected, to add some (up to 15 wt %, preferably 2-8 wt %) of the olein fraction, that is obtainable by the fractionation of a blend of hardened soy bean oil and hardened cottonseed oil, to the fatblend. Soybean oil and cottonseed oil from every source can be used to prepare our mid-fractions. The best fatblends are obtained, when these blends contain a relatively high amount of trans-hardened oils. These trans-hardened oils are obtained, when the hardening of the oils is carried out, e.g. with a sulfidised Ni-catalyst, e.g. Pricat 9908' which contains about 0.1-0.2 wt % Ni and which is used at pressures of about 1 bar and temperatures of about 150.degree.-250.degree. C. This way hardened oils can be obtained that consist of more than 40% of trans-hardened oils.
The fractionation product is obtained by wet fractionation. The solvents normally used are hexane and acetone. When acetone is used the fractionation is carried out by using more than 3 vol units acetone per weight unit of oil (so: e.g. 5 l acetone per 1 kg oil).
The fractionation is carried out by mixing the ingredients (oil mixture) with acetone of 35.degree. C. or more in the appropriate ratio. The mixture is cooled to about -15.degree. to +15.degree. C., e.g. 0.degree. C. At this temperature a crystallised product can be separated from a supernatent liquid e.g. by filtering or centrifugation. The solid so obtained is mixed again with acetone of 35.degree. C. or more until a solution is obtained. This solution is cooled to a temperature of 16.degree.-24.degree. C., depending on the product that is desired. Here again a solid product will be formed, that can be separated from a liquid acetone containing fraction. After working up of the acetone fraction, by removing the acetone, the required mid-fraction is obtained.
The compositions according to the invention can be obtained in different ways. The preferred way consists of making a blend of unhardened soybean oil and cottonseed oil, hardening this blend in the way described above, wet fractionating the hardened product as described above, whereupon the desired product is obtained. However in another embodiment the soybean oil and cottonseed oil are treated separately. This way two mid-fractions are obtained after the wet fractionations. These fractions can be admixed to give the required product. In another sequence the two unhardened oils can be hardened separately, after which the hardened oils are combined and wet-fractionated as a blend.
Of course also chocolate coatings and food products containing the blends of the invention are part of the invention.